Multiple Instances of Ancient Balancing Selection Shared Between Humans and Chimpanzees
7 March 2013
Investigations into the total DNA (genome) of humans and animals can explain the importance of different regions of the DNA and the underlying selection pressure. A comparison of the chimpanzee and human genome has given new insights with regards to their ancestors.
Studies on the genomes of different people reveal regions that show variation. In most cases, these are point mutations in a single building brick, called single nucleotide polymorphisms (SNP). It appears that several variants of the same gene or region remain present in the human population, which is explained by the term "balancing selection". Similarly, the SNPs of the chimpanzee have been identified. The comparison between the human and chimpanzee SNP map by several research institutes, including the BPRC, brought forward a particular phenomenon. Some combinations of SNPs were shared between humans and chimpanzees. This suggests that these ancient variants were already present in a distant ancestor that must have lived more than five million years ago. In both species, these variants have been retained by "balancing selection". These findings were described in the leading journal Science (http://www.sciencemag.org/content/early/2013/02/13/science.1234070.abstract)